Skylar Grey & Karmin Perform “I Need a Doctor” at Lollapalooza (Video)

Lollapalooza celebrated its 20th year anniversary this year at Grant Park in Chicago with a slew of stars and musical acts. One of the musicians in attendance was Karmin as they performed Dr. Dre’s hit “I Need a Doctor.” Even songwriter and featured hook maestro Skylar Grey joined the pair on stage.